The present invention relates generally to a cleaning composition and process for removal of organic, organometallic, and/or metallic residues from semiconductor substrates, and also to a composition which can be used to apply controlled and predetermined etch rates on selected metal substrates. More particularly, the present invention relates to compositions including 2-carbon atom linkage alkanolamines, in particular 2-(2-aminoethylamino)-ethanol (AEEA), which are useful for removing semiconductor device fabrication residues and in some embodiments a small predetermined amount of substrate from semiconductor-type substrates. The invention also includes the processes of using the compositions of the present invention to clean and/or etch substrates particularly containing exposed aluminum, titanium, copper, tungsten, and/or alloys thereof.
As integrated circuit manufacturing has become more complex and the dimensions of circuit elements fabricated on silicon or other semiconductor wafers have become smaller, continued improvement in techniques used to remove residues formed from such materials has been required. Resists, used to mask substrates such that patterned material can be added, need to be removed from substrates.
Many formulations have been developed to remove both positive and negative resist. A resist includes polymeric material, which may be crosslinked or hardened by baking. Therefore, a simple combination of solvents will often remove resists, though time and temperature constraints in the manufacturing process have in general moved the industry to slightly more aggressive compounds.
Early compositions used for removing photoresists and other substrate layers have, for the most part, been highly flammable. In addition, reactive solvent mixtures can exhibit an undesirable degree of toxicity and are generally hazardous to both humans and the environment. Moreover, these compositions are not only toxic, but their disposal is costly, since they must be disposed of as a hazardous waste. In addition, these prior art compositions generally have a severely limited bath life and, for the most part, are not recyclable or reusable.
U.S. Pat. No. 4,617,251 to Sizensky, which issued on Oct. 14, 1986, describes a solution for removing polymeric resists that contains from 2 to 98% of an organic polar solvent and from 2 to 98% of an amine, particularly AEEA, 2-(2-aminothothoxy)-ethanol (DGA), or a mixture thereof. The patent teaches that the formulation is effective even on baked resists which have been exposed to temperatures of up to 200xc2x0 C. for up to 30 minutes. The patent suggests that up to 50% of water or more can be added, and also that wetting agents and surfactants can be added.
Other prior art compositions for removing photoresists include inorganic alkalis in water, and polar organic solvents for positive photoresists. Polar organic solvents are used generally at temperatures below 50xc2x0 C. Mixtures of alkanolamines in water can be used for most types of resists.
Additionally, because many of the toxic components of such compositions are highly volatile and subject to unduly high evaporation rates, the compositions require special human and environmental safety precautions to be taken during storage and use of said compositions.
The resists may in some locations be altered, for example by etching, into various compounds, which incorporate the altered resist, as well as some usually altered substrate. For example, oxygen plasma oxidation is often used for removal of resists or other polymeric materials after their use, during the fabrication process has been completed. Such high energy processes typically result in the formation of organometallic and other residues, for example metal oxides, on sidewalls of the structures being formed in the fabrication process. Other etching, including the use of directed energy and/or chemical etching, leave different types of residue, for example organometallic compounds and/or metal fluorides. Finally, direct layer deposition using convertible organometallic compounds, which may or may not require etching to form a pattern, may leave yet other types of residues. These residues must be removed without substantially altering the underlying substrate.
U.S. Pat. No. 6,372,050 teaches a composition for cleaning residue from a substrate that contains 5 to 50% of a solvent selected from a particular group that includes M-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide, and many others; 10 to 90% of an alkanolamine selected from diethyleneglycolamine (DGA), monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), AEEA, and mixtures thereof; from 0.1 to 10% of a carboxylic acid selected from formic acid, acetic acid, phthalic acid, salicylic acid, oxalic acid, and many others; and 1 to 40% water.
A variety of metal and other layers are commonly employed in integrated circuit fabrication, including aluminum, aluminum/silicon/copper, copper, titanium, titanium nitride, titanium/tungsten, tungsten, silicon oxide, polysilicon crystal, and the like. The use of such different layers results in the formation of different organometallic residues in the high energy processes. Further, there is almost always at least two, but in some cases there may be more than two substrate types on an outer layer to be cleaned. A cleaning composition is often designed to be compatible with a single substrate exposed to the cleaning composition.
A variety of residue removal compositions and processes suitable for integrated circuit fabrication have been developed and marketed by EKC Technology, Inc. (hereinafter xe2x80x9cEKCxe2x80x9d), the assignee of the present application. Some of these compositions and processes are also useful for removing photoresist, polyimide, or other polymeric layers from substrates in integrated circuit fabrication, and EKC has also developed a variety of compositions and processes specifically for removing such polymeric layers from substrates in integrated circuit fabrication. Additionally, EKC has developed a variety of compositions and processes to selectively remove specific substrate compositions from a substrate surface at a controlled rate. Such compositions and processes are disclosed in the following commonly assigned issued patents:
U.S. Pat. No. 6,367,486 to Lee et al., which issued on Apr. 9, 2002, entitled Ethylenediaminetetraacetic acid or its ammonium salt semiconductor process residue removal process;
U.S. Pat. No. 6,313,039 to Small et al., which issued on Nov. 6, 2001, entitled Chemical mechanical polishing composition and process;
U.S. Pat. No. 6,276,372 to Lee, which issued on Aug. 21, 2001, entitled Process using hydroxylamine-gallic acid composition;
U.S. Pat. No. 6,251,150 to Small et al., which issued on Jun. 26, 2001, entitled Slurry composition and method of chemical mechanical polishing using same;
U.S. Pat. No. 6,248,704 to Small et al., which issued on Jun. 19, 2001, entitled Compositions for cleaning organic and plasma etched residues for semiconductors devices;
U.S. Pat. No. 6,242,400 to Lee, which issued on Jun. 5, 2001, entitled Method of stripping resists from substrates using hydroxylamine and alkanolamine;
U.S. Pat. No. 6,235,693 to Cheng et al., which issued on May 22, 2001, entitled Lactam compositions for cleaning organic and plasma etched residues for semiconductor devices;
U.S. Pat. Nos. 6,187,730 and 6,221,818, both to Lee, which issued on Feb. 13, 2001 and on Apr. 24, 2001, respectively, entitled Hydroxylamine-gallic compound composition and process;
U.S. Pat. No. 6,156,661 to Small, which issued on Dec. 5, 2000, entitled Post clean treatment;
U.S. Pat. No. 6,140,287 to Lee, which issued on Oct. 31, 2000, entitled Cleaning compositions for removing etching residue and method of using;
U.S. Pat. No. 6,121,217 to Lee, which issued on Sep. 19, 2000, entitled Alkanolamine semiconductor process residue removal composition and process;
U.S. Pat. No. 6,117,783 to Small et al., which issued on Sep. 12, 2000, entitled Chemical mechanical polishing composition and process;
U.S. Pat. No. 6,110,881 to Lee et al., which issued on Aug. 29, 2000, entitled Cleaning solutions including nucleophilic amine compound having reduction and oxidation potentials;
U.S. Pat. No. 6,000,411 to Lee, which issued on Dec. 14, 1999, entitled Cleaning compositions for removing etching residue and method of using;
U.S. Pat. No. 5,981,454 to Small, which issued on Nov. 9, 1999, entitled Post clean treatment composition comprising an organic acid and hydroxylamine;
U.S. Pat. No. 5,911,835 to Lee et al., which issued on Jun. 15, 1999, entitled Method of removing etching residue;
U.S. Pat. No. 5,902,780 to Lee, which issued on May 11, 1999, entitled Cleaning compositions for removing etching residue and method of using;
U.S. Pat. No. 5,891,205 to Picardi et al., which issued on Apr. 6, 1999, entitled Chemical mechanical polishing composition;
U.S. Pat. No. 5,672,577 to Lee, which issued on Sep. 30, 1997, entitled Cleaning compositions for removing etching residue with hydroxylamine, alkanolamine, and chelating agent;
U.S. Pat. No. 5,482,566 to Lee, which issued on Jan. 9, 1996, entitled Method for removing etching residue using a hydroxylamine-containing composition;
U.S. Pat. No. 5,399,464 to Lee, which issued on Mar. 21, 1995, entitled Triamine positive photoresist stripping composition and post-ion implantation baking;
U.S. Pat. No. 5,381,807 to Lee, which issued on Jan. 17, 1995, entitled Method of stripping resists from substrates using hydroxylamine and alkanolamine;
U.S. Pat. No. 5,334,332 to Lee, which issued on Aug. 2, 1994, entitled Cleaning compositions for removing etching residue and method of using;
U.S. Pat. No. 5,279,771 to Lee, which issued on Jan. 18, 1994, entitled Stripping compositions comprising hydroxylamine and alkanolamine;
U.S. Pat. No. 4,824,763 to Lee, which issued on Apr. 25, 1989, entitled Triamine positive photoresist stripping composition and prebaking process; and
U.S. Pat. No. 4,395,348 to Lee, which issued on Jul. 26, 1983, entitled Photoresist stripping composition and method;
the entire disclosures of all of which are incorporated herein for all purposes by express reference thereto. These compositions have achieved substantial success in integrated circuit fabrication applications.
U.S. Pat. No. 5,997,658 describes a remover for photoresist and etching residue that contains water, an amine, and a corrosion inhibitor including benzotriazole, gallic acid, or both.
As a result of a continuous effort to decrease critical dimension size in the integrated circuit industry, such as in the fabrication of sub-micron size devices, etching residue removal and substrate compatibility with chemicals employed in wet processing is becoming more and more critical for obtaining acceptable yield in very large scale integration (VLSI) and ultra large scale integration (ULSI) processes. The effectiveness of residue removal by etching, to a large extent, depends on the composition of the surfaces or materials to be etched and the composition of the etchant, as well as many other variables too numerous to mention. The composition of such etching residue is generally made up primarily of the etched substrates, underlying substrate, etched and/or ashed photoresist, and etching gases. The substrate compatibility of the wafers with wet chemicals is highly dependent on the processing of the polysilicon, multilevel interconnection dielectric layers, and metallization in thin film deposition, etching and post-etch treatment of the wafers. Processing conditions are often quite different from one fabrication process to another, making it difficult to apply a particular composition to obtain both effective residue removal and substrate compatibility. For example, some compositions have produced corrosion on certain metal substrates, such as those including a titanium metal layer. Titanium has become more widely used in semiconductor manufacturing processes. It is employed both as a barrier layer to prevent electromigration of certain atoms and as an antireflector or refractory metal layer on top of other metals. Used in such a capacity, the layer is often very thin, and corrosion or etching during cleaning operations may compromise the purpose of the layer.
Hydroxylamine (HA) formulations have been found to be useful in the removal of substrate, for example as an etchant used in chemical-mechanical etching processes, as described in U.S. Pat. Nos. 6,313,039; 6,251,150; and 6,117,783.
Hydroxylamine formulations have also been useful in removing photoresists, such as is found in U.S. Pat. Nos. 5,279,771 and 5,381,807, which describe formulations containing hydroxylamine, an alkanolamine, and optionally a polar organic solvent. Hydroxylamine formulations have also been useful in removing etching residue, such as is found in U.S. Pat. No. 5,334,332, which describes a formulation containing hydroxylamine, an alkanolamine, water, and a chelating agent. Hydroxylamine-containing formulations designed to remove residues are known to be aggressive to metals, particularly to titanium film and under more aggressive process conditions to aluminum film.
As a result, various formulations have been developed to control the corrosion. The attack of titanium can be moderated by using different chelator, e.g., such as disclosed in U.S. Pat. No. 6,276,372, and/or by selecting a class of alkanolamine with 2-carbon linkage(s), which is disclosed, e.g., in U.S. Pat. No. 6,121,217. For example, other formulations include those disclosed in: U.S. Pat. Nos. 6,276,372, 6,221,818, and 6,187,730, which each describe a hydroxylamine formulation with a gallic compound (as opposed to catechol) and an alcohol amine; U.S. Pat. Nos. 6,242,400, which describes a hydroxylamine formulation with an alcohol amine and a polar organic solvent; U.S. Pat. Nos. 6,156,661 and 5,981,454, which each describe a buffered hydroxylamine formulation with an organic acid; U.S. Pat. Nos. 6,140,287 and 6,000,411, which each describe a hydroxylamine formulation with an alkanolamine and a chelating agent; U.S. Pat. No. 6,121,217, which describes a hydroxylamine formulation with an alkanolamine and gallic acid or catechol; U.S. Pat. No. 6,110,881, which describes a hydroxylamine formulation with an organic solvent, water, and a chelating agent; U.S. Pat. No. 5,911,835, which describes a nucleophillic amine compound formulation with an organic solvent, water, and a chelating agent; and U.S. Pat. Nos. 5,902,780, 5,672,577, and 5,482,566, which each describe a hydroxylamine formulation with an alkanolamine, water, and a dihydroxybenzene chelating agent.
U.S. Pat. No. 5,997,658 to Peters et al. describes a hydroxlamine-free photoresist stripping and cleaning composition, for use particularly of copper or titanium substrates, having about 70 to 85% by weight of an alkanolamine, about 0.5 to 2.5% by weight of benzotriazole, about 0.5 to 2.5% by weight of gallic acid and the remainder being water. Alkanolamines include N-methylethanolamine (NMEA), monoethanolamine (MEA), diethanolamine, mono-, di-, and tri-isopropanolamine, 2-(2-aminoethylamino)-ethanol, 2-(2-aminoethoxy)-ethanol, triethanolamine, and the like. The preferred alkanolamine is N-methylethanolamine (MEA).
Additionally, U.S. Pat. No. 5,928,430 to Ward et al., entitled Aqueous stripping and cleaning compositions containing hydroxylamine and use thereof, describes an aqueous stripping composition comprising a mixture of about 55% to 70% by weight of a polar amine solvent, about 22.5 to 15% by weight of a basic amine, especially hydroxylamine, gallic acid as a corrosion inhibitor, and water. U.S. Pat. No. 5,419,779 to Ward describes a stripping composition containing water, 22.5 to 15% by weight of hydroxylamine, 55% to 70% monoethanolamine, and preferably up to about 10% by weight of a corrosion inhibitor, particularly one selected from the group consisting of catechol, pyrogallol, anthranilic, acid, gallic acid, and gallic ester.
Other cleaning-type compositions exist, for example as found in U.S. Pat. No. 6,261,745 to Tanabe et al., entitled Post-ashing treating liquid compositions and a process for treatment therewith, which describes a post-ashing treating liquid composition comprising a salt of hydrofluoric acid with a base free from metal ions, a water-soluble organic solvent, water, and an acetylene alcohol/alkylene oxide adduct.
Other prior art, e.g., U.S. Pat. Nos. 6,372,050, 6,326,130, 6,268,323, 6,261,745, 5,997,658, 5,417,877, and 4,617,251, inter alia, have demonstrated the corrosion of the aluminum metal film caused by various amines and other compounds in photoresist stripper formulations.
However, further development of integrated circuits and their fabrication processes have created a need for improvement in residue removal compositions and processes.
One important problem with respect to residue removers is the permissible operating temperature. Generally, higher temperatures are preferred by manufacturers to reduce particle counts and to increase process speed. There are generally three limitations on the operating temperature: safety concerns, composition longevity, and etch rates.
It is usually desirable that the operating temperature should not exceed the flash point of the mixture. The flash point is the lowest temperature at which a liquid can form an ignitable mixture in air near the surface of the liquid. The lower the flash point, the easier it is to ignite the material. For example, gasoline has a flash point of xe2x88x9240xc2x0 C., and it is therefore more flammable than ethylene glycol which has a flash point of 111xc2x0 C. (232xc2x0 F.). Flammable liquids that are water miscible may have increased or decreased flash points when mixed with water. Often, the flash point of a mixture will be classified the same as that of the liquid with the lowest flash point.
This problem has been addressed in the prior art by limiting process temperatures. U.S. Pat. No. 5,419,779 to Ward describes a process for removing an organic coating from a substrate by applying a composition consisting of about 62% by weight of MEA, about 19% by weight HA, a corrosion inhibitor which includes gallic acid and gallic acid esters, and water. This patent limits the operating temperature to between 40xc2x0 C. and 75xc2x0 C. The flash point of MEA is 93xc2x0 C. Typically, however, manufacturers use strippers and residue removers at higher temperatures to accelerate residue and especially polymer removal.
Even if the composition is held below its flash point, low boiling temperature compounds will nevertheless preferentially distill out of the stripper or residue cleaner composition over time. The compositions may change with time because they are generally stored for up to several days at operating temperatures during use. In many instances, the flash point of a mixture changes as certain components are distilled from the mixture. The cleaning and substrate etching characteristics of a formulation will change as the amounts of the components change.
Some manufacturers provide replenishing solutions that contain one or more components that are lost over time while storing the residue remover at operating temperature. Since low-boiling-temperature organics are preferentially lost and these low-boiling-temperature organics have lower flash points than high-boiling-temperature organics, this replenishing formulation typically has a very low flash point. During the process of adding the replenishing solutions, the system may have localized areas where the temperature exceeds the flash point of the liquid, which can result in dangerous conditions. Advantageously, for certain embodiments of this invention, replenishing solutions consist essentially of water and, optionally, hydroxylamine and/or a hydroxylamine derivative. The replenishing solutions are preferably substantially free of alkanolamines and polar organic solvents, and optionally chelating agents and/or corrosion inhibitors.
The etch rates of most residue remover formulations increases with increasing process temperature. Some manufacturers suggest using formulations at low temperatures, such as at 30xc2x0 C., to provide low etch rates at xe2x80x9cnormalxe2x80x9d operating temperatures. Lower temperatures do not provide adequate removal of tougher residues, which may include polymeric material, within an feasible processing time.
It is possible to use highly reactive components in residue removers, which allows elimination of many solvents and other organics. Fluoride-containing compositions can be used for oxide etch residue. This allows higher flashpoints for mixtures, in some cases exceeding 105xc2x0 C. However, aluminum and titanium etch rates, at ambient temperatures, of 3 to 6 xc3x85/minute are found in commercial inhibited formulations. Therefore, higher temperatures are not practicable for such formulations.
Finally, there may be more than one substrate exposed to a cleaner. Many cleaner formulations exhibit reduced etching activity for one substrate but poor etching activity with other substrate(s). Different etch rates will often produce undesired results.
Accordingly, one object of the invention is to provide a family of photoresist and residue removing compositions which overcomes the above and other stated problems with the prior art. Another object of this invention is to provide an improved composition for residue removal and process using such a composition suitable for meeting current semiconductor fabrication requirements. It is another object of the invention to provide a process which is suitable for meeting the above objects. The attainment of the foregoing and related objects, advantages, and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention, taken together with the examples and claims, as described herein.
One embodiment of the invention is a residue removing composition which is effective for removing residues such as resists and etching residues after etching processes, e.g., plasma etching, which are undesired byproducts generated during the fabrication of integrated circuits on silicon wafers and similar processes, and also resists or other undesired materials, but does not attack the different underlying substrate metallurgies and insulation layers used in integrated circuit fabrication.
One embodiment of the invention is a residue removing composition that is effective for removing residues, such as resists and etching residues, after etching processes, e.g., plasma etching, which residues can be undesired byproducts generated during the fabrication of integrated circuits on semiconductor wafers, but which composition does not aggressively attack underlying titanium and/or aluminum used in integrated circuit fabrication.
One embodiment of the invention is a residue removing composition that, when used as an etchant or when used as a residue remover/etchant, provides a controlled slow etch rate on various substrates, in addition to cleaning any residues.
One embodiment of the invention is a residue removing composition that, when used as an etchant or when used as a residue remover/etchant, provides a controlled slow etch rate on various substrates, in addition to cleaning any residues, wherein the etch rates on the different metal compositions are substantially the same, or alternatively differ in a predetermined amount.
One embodiment of the invention is a residue removing composition that is effective for removing residues, such as resists and etching residues, and which composition exhibits a low etch rate for a variety of metallic substrates while used at higher temperature, i.e., greater than 70xc2x0 C., preferably greater than 90xc2x0 C., for example in some instances greater than 110xc2x0 C.
One embodiment of the invention is a residue removing composition that is effective for removing residues, such as resists and etching residues, and which composition advantageously has a low formulation loss and a low composition change (excluding water and in some cases hydroxylamine), when stored and used at relatively higher temperatures.
One embodiment of the invention is a residue removing composition that is effective for removing residues, such as resists and etching residues, and which composition has a flash point in excess of 115xc2x0 C., preferably in excess of 125xc2x0 C., for example in excess of 130xc2x0 C. Another embodiment of the invention is a residue removing composition that is effective for removing residues such as resists and etching residues and which contains less than 10%, preferably less than 5%, and more preferably is substantially free of components with a flash point below about 115xc2x0 C., preferably below about 125xc2x0 C., for example below about 130xc2x0 C.
One embodiment of the invention is a residue removing composition that is effective for removing residues, such as resists and etching residues, and which composition contains less than 10%, preferably less than 5%, and more preferably is substantially free of organic components having a boiling point below about 199xc2x0 C., preferably below about 215xc2x0 C., for example below about 235xc2x0 C.
One embodiment of the invention is a residue removing composition that is effective for removing residues, such as resists and etching residues, and which composition contains less than 10%, preferably less than 5%, and more preferably is substantially free of organic components having a boiling point not between about 199xc2x0 C. and 290xc2x0 C., preferably between about 215xc2x0 C. and 290xc2x0 C.
One embodiment of the invention is a residue removing composition that is effective for removing residues, such as resists and etching residues, and which composition contains less than 10%, preferably less than 5%, and more preferably is substantially free of organic components having a boiling point not between about 235xc2x0 C. and 260xc2x0 C.
One embodiment of the invention is a family of a residue removing compositions that contain AEEA and that are effective for removing residues, such as resists and etching residues, while being less aggressive to titanium and/or aluminum substrates than similar compositions with other alkanolamines different than AEEA.
One embodiment of the invention is a family of solvent-based residue removing compositions that contain AEEA and that are effective for removing residues, such as resists and etching residues, while being useful for a variety of metallic and dielectric substrates, wherein the flash point of the cleaning composition is greater than about 120xc2x0 C., preferably greater than about 125xc2x0 C., more preferably greater than about 130xc2x0 C.
One embodiment of the invention is a family of solvent-based residue removing compositions that contain AEEA and that are effective for removing residues, such as resists and etching residues, while being useful for a variety of metallic and dielectric substrates, wherein the flash point of the cleaning composition is greater than about 120xc2x0 C., preferably greater than about 125xc2x0 C., more preferably greater than about 130xc2x0 C. Another embodiment is a method of cleaning polymeric material, etching residue, or both from a semiconductor substrate, which method includes using the aforementioned family of solvent-based residue removing compositions in a process operated at a temperature between about 90xc2x0 C. and about 120xc2x0 C.
One embodiment of the invention is a family of solvent-based residue removing compositions that contain AEEA and that are effective for removing residues, such as resists and etching residues, while being useful for a variety of metallic and dielectric substrates, wherein the flash point of the cleaning composition is greater than about 125xc2x0 C. Hydroxylamine does not have a reported flash point.
Another embodiment of the invention is a multicomponent residue removing composition that is effective for removing residues, such as resists and etching residues, and that contains less than 10%, preferably less than 5%, and more preferably is substantially free of volatile organic components having a boiling point not between about 220xc2x0 C. and about 250xc2x0 C. Hydroxylamine is not considered a volatile organic component for these purposes.
Another embodiment of this invention is a family of residue removers that etch various substrates at a predetermined rate, for example etching aluminum, titanium, tungsten, and alloys thereof at approximately the same rate.
Another embodiment of this invention a family of residue removers that etch various substrates at a predetermined rate, for example etching aluminum at a rate comparable to chemical mechanical etching solutions, but are not aggressive to other selected metals, for example titanium and alloys thereof.
Another embodiment of the invention is a composition and process that is suitable for removing residues from wafers and other substrates including one or more metal or metal alloy layers without substantial attack on such layers.
A residue removal and/or etching composition in accordance with this invention includes 2-(2-aminoethylamino)-ethanol (AEEA), which is an alcohol amine compound that has a relatively high boiling point, a relatively high flash point, and a relatively low (in some cases, non-existent) etch rate under standard process conditions for metallic substrates or layers.
In some embodiments of the invention, the attainment of these and related objects may be achieved through use of the residue removal and/or etching composition comprising a derivative of 2-(2-aminoethylamino)-ethanol formed by adding substituting groups onto a 2-(2-aminoethylamino)-ethanol base.
A process for removing a residue from a substrate and/or for etching a metal or metal alloy on a substrate, in accordance with this invention, includes contacting the substrate with a composition that contains a two-carbon atom linkage alkanolamine compound, particularly 2-(2-aminoethylamino)-ethanol, for a time and at a temperature sufficient to remove the residue from the substrate and/or to selectively etch the metal and/or metal alloy from the substrate.
In practice, is has been found that use of a two-carbon atom linkage alkanolamine compound gives a residue removing composition that reduces attack on some substrates, e.g., titanium, to a value substantially less than prior cleaning compositions. At the same time, the two-carbon-atom-linkage-alkanolamine-compound-containing composition gives equivalent performance as a residue removing composition.